(1) Field of the Invention
This invention relates to energy storage, and more particularly to magnetic energy storage.
(2) Description of the Related Art
Many potential applications of pulsed power require tens of megajoules of energy that can be discharged over times from a few microseconds to a second. For most of these applications to be realized as practical devices, the energy density of the entire device (storage, switching, and power conditioning) must be greater than ten megajoules/m3 with a goal on the order of 100 megajoules/m3.
While there have been great strides in the energy density of electrostatic energy storage (capacitors), the current state-of-the-art is still only a few megajoules/m3 and it will require major breakthroughs in materials and capacitor design to reach even ten megajoules/m3.
Magnetic energy storage can typically be three orders of magnitude higher energy density than electrostatic energy density. Magnetic energy storage is frequently not utilized as a basic power source because the stray magnetic fields sometimes interfere with electronic or conducting parts near the energy storage and opening switches that are needed to extract the energy usually waste a large fraction of the stored energy.
When the leads are connected in parallel the system resembles a so called XRAM circuit (Marx spelled backward, see, e.g.,: Ford, R. D.; Hudson, R. D.; Klug, R. T., “Novel hybrid XRM current multiplier”. IEEE Transactions on Magnetics, vol. 29, 6th symposium on Electromagnetic Launch Technology, Austin, Tex., USA, 28-30 April 1992.) January 1993. p.949-53; Botcharov, Yu. N.; Efimov, I. P.; Krivosheev, S. I.; Shneerson, G. A. (Edited by: Stallings, C.; Kirbie, H.) “The transient processes end energy balance in inductive energy storage including ferromagnetic opening switch”., Proceedings of the 12th IEEE International Pulsed Power Conference-Monterey, Calif., USA, 27-30 June 1999. IEEE—Piscataway, N.J., USA 1999.p.1250; Kanter, M.; Cerny, R.; Shaked, N.; Kaplan, Z. (Edited by: Prestwich, K. R.; Baker, W. L.) Repetitive operation of an XRAM circuit.” Proceedings of 9th International Pulsed Power Conference, Albuquerque, N.Mex., USA, 21-23 June 1993 IEEE—Piscataway, N.J., USA 1993. p.92).